The Department of Justice's (DOJ) Bureau of Justice Assistance (BJA) administers the Adult Drug Court Discretionary Grant Program, which provides financial and technical assistance to develop and implement adult drug-court programs. Findings of this report show that drug-court program participation was generally associated with lower recidivism; and evaluations reporting recidivism data for 32 programs showed that drug-court program participants were generally less likely to be re-arrested than comparison group members drawn from criminal court, with differences in likelihood reported to be statistically significant for 18 of the programs. Cost-benefit analyses showed mixed results: across studies showing re-arrest differences, the percentages of drug- court program participants re-arrested were lower than for comparison group members by 6 to 26 percentage points; drug court participants who completed their program had re-arrest rates 12 to 58 percentage points below those of the comparison group; GAO's analysis of evaluations reporting relapse data for eight programs showed that drug-court program participants were less likely than comparison group members to use drugs, based on drug tests or self- reported drug use, although the difference was not always significant; and of the studies assessing drug-court costs and benefits, the net benefit ranged from positive $47,852 to negative $7,108 per participant. As of June 2010, there were over 2,500 drug courts operating nationwide, of which about 1,400 target adult offenders. Performance data were from DOJ in fiscal year 2010; GAO reviewed evaluations of 32 drug- court programs and 11 cost-benefit studies issued from February 2004 through March 2011.